A New Stereochemical Model from NMR for Benzoylated
Cyclodextrins, Promising New Chiral Solvating Agents for the
Chiral Analysis of 3,5-Dinitrophenyl Derivatives
posted on 1997-02-21, 00:00authored byGloria Uccello-Barretta, Angela Cuzzola, Federica Balzano, Rita Menicagli, Anna Iuliano, Piero Salvadori
Hexakis(2,3-di-O-benzoyl)-α-cyclodextrin and
hexakis(2,3,6-tri-O-benzoyl)-α-cyclodextrin have
been
employed as chiral solvating agents (CSAs) for the NMR determination of
the enantiomeric
composition of derivatives of chiral amines, amino alcohols, alcohols,
carboxyl acids, and amino
acids bearing a 3,5-dinitrophenyl moiety. The conformational
features of the two cyclodextrins
have been carefully analyzed by NMR spectroscopy, and the origin of the
symmetry change (C6 →
C3), detected by NMR for
hexakis(2,3-di-O-benzoyl)-α-cyclodextrin in
CDCl3, has been clarified.